{keyword}') Union All Select Null,null,null,null,null,null,null-- Hofz Page

: A WAF can often block these types of patterned attacks automatically.

The string you provided is a . Specifically, it is designed to exploit a vulnerability in a database-driven application to extract unauthorized data. : A WAF can often block these types

: Use parameterized queries so that user input is never executed as code. : A WAF can often block these types

: This is likely a "canary" or a unique identifier used by automated security scanners to confirm if the injection was successful. What should you do? : A WAF can often block these types

: This part attempts to "break out" of a standard SQL query. It uses a closing quote and parenthesis to terminate whatever the original developer intended the query to do.